IMPROVEMENT OF MOLYBDENUM BLACKENING TECHNOLOGY

Subject of Research. The paper considers various methods for coating synthesis on molybdenum and heatproof materials. We propose the method of molybdenum blackening technology improvement. Method. The first method involves holding the sample in deionized water for some time after pretreatment, and the second one is characterized by its absence. During the experiment, the samples were taken three-stage treatment comprising etching in an aqueous solution containing HF and HCl for ten minutes. After that, the samples were immersed in a container with an ammonium molybdate solution, where the deposition of coating was carried out by electrochemical method. Main Results. The studied black coating is high resistent, in particular, it can be washed out only using the strong acid (for instance, the nitric acid) and can not be eliminated with alkali solution as well as wire brushing. But the first sample coating is short-lived and it comes off the sample surface in course of time. During the second experiment with the modified technology the applied coating becomes cracked eventually, but it does not break away from the surface. The coated samples were stored at normal temperature and pressure. The study of coated samples deterioration was carried out by Inspect SEM FEI scanning electronic microscope. Practical Relevance. The study results can be used for design of optical equipment new samples, in particular, for applying light-absorbing coating on molybdenum parts. The following black molybdenum coating technology improvement can be based on this work as well.